All power amps “good ones” sound the same.

[JohnRoberts]

He passed a couple of years ago...

I actually have a limiter he made back in his earlier college days and he was always helpful the few times I had questions. Very passionate about sound...
RIP

Yes David (RIP) was pretty active in the local AES chapter in Michigan IIRC.

Back in the 80s before I exited the audiophile market in disgust, I sent David (DLC design) my latest phono preamp just to get his opinion. I trusted him to give it a fair listen. Without my knowledge he forwarded my preamp to Larry Greenhill a well respected industry hifi reviewer. 

I love the WWW... here is a copy of the 1985 issue of Stereophile where they published Greenhill's favorable review of my last preamp (P-100).  https://worldradiohistory.com/Archive-All-Audio/Stereophile/80s/Stereophile-Vol-8-No-2.pdf Page 52.

It made me feel really good to read that nice review again, but I already had one leg out the door, back then escaping from the audiophoolishness. Shortly after that I accepted a position at Peavey. Can't get much further away from audiophools than that. 

JR

 

[Gold]

Having a box that says A/B/X on it doesn't mean by using it you are conducting a scientifically valid double blind whoopee ha ha. I have this on my console yet I've studiously called it A/B testing and have not claimed it's scientifically valid.

 

[user 37518]

Dear Mr. Science,

You said you wouldn’t believe me unless I conducted a double blind whoopee ha ha. I’m willing to put up double that. Pulling a number out of my a** I’d estimate $100K USD. I’m willing to put up $200K. Should be easy money for you.

Whatever you are taking you should consider quitting.

 

[JohnRoberts]

Whatever you are taking you should consider quitting.

be nice...

JR

 

[Gold]

Whatever you are taking you should consider quitting.

I’m not sure why you are upset. You said the only way to prove my point was with a double blind whoopee ha ha. I am willing to finance such a study and have the results published in a peer reviewed journal.

I estimate the cost of setting up such a study at $100K. I’m sure you’ve done this before as you are so insistent that it’s the only way to reach a valid conclusion. I’d bet another 100k on top of that. Looser owes $200K. I don’t know what more you could ask for.

 

[JohnRoberts]

I’m not sure why you are upset. You said the only way to prove my point was with a double blind whoopee ha ha. I am willing to finance such a study and have the results published in a peer reviewed journal.

I estimate the cost of setting up such a study at $100K. I’m sure you’ve done this before as you are so insistent that it’s the only way to reach a valid conclusion. I’d bet another 100k on top of that. Looser owes $200K. I don’t know what more you could ask for.

please be nice too...

JR

 

[boji]

There will always be a need for subjective tests to compliment data driven tests.
Reason is, any objective quantification of subjective experience modifies subjective preference, especially once the subject knows they can be gamed.

https://www.youtube.com/watch?v=-2SvMeyeOgQ

 

[user 37518]

I’m not sure why you are upset. You said the only way to prove my point was with a double blind whoopee ha ha. I am willing to finance such a study and have the results published in a peer reviewed journal.

I estimate the cost of setting up such a study at $100K. I’m sure you’ve done this before as you are so insistent that it’s the only way to reach a valid conclusion. I’d bet another 100k on top of that. Looser owes $200K. I don’t know what more you could ask for.

I'm not sure how are you estimating that figure for a study, many of the participants do it for free, I am a lecturer at a university and currently finishing my PhD in EE so I am quite familiar with the academic world, the acoustics department has asked me to participate in their studies, which I have done it for free, they have their own audiometry testers and many times the equipment or materials are loaned or donated, if every study had to cost $100K the department would be seriously underfunded. Not sure what are you betting on either, loser of what? what do I have to win or lose for that matter?

 

[user 37518]

There will always be a need for subjective tests to compliment data driven tests.
Reason is, any objective quantification of subjective experience modifies subjective preference, especially once the subject knows they can be gamed.

https://www.youtube.com/watch?v=-2SvMeyeOgQ

You can conduct a test based on subjective opinions and still be scientific, you can make a double blind test and ask people which of the following you prefer? that is subjective, the individual is making his own decision based on what he likes, but the study is objective, they are not biasing the test subject with anything that could influence his decision other than what he is listening. If you show the amplifier to the listener and tell them which one is more expensive, you will bias their opinion, this happens not only with audio, for instance, wine is the same thing, if you tell someone that this bottle costs $10 and this other costs $1000, even if they are the same wine with a different label, most people tend to prefer the $1000 wine.

I've seen this many times with little things in life, if you go to the doctor and the doctor charges $10 will he give you enough confidence? what about a $400 doctor?, perhaps the $10 is a better M.D. but the price doesn't inspire that much, perhaps if you get to know the cheap doctor you will realize that he is great thou.

 

[Gold]

I'm not sure how are you estimating that figure for a study, many of the participants do it for free,

Just a wild guess. Renting space, securing equipment, paying people to make sure the test will pass a peer review.

Not sure what are you betting on either, loser of what? what do I have to win or lose for that matter?

I am betting I can design a test that will show a statistically significant difference between the sound of two amplifiers into a single set of speakers. Using a test that can be peer reviewed and the results published in an academic journal.

 

[user 37518]

Just a wild guess. Renting space, securing equipment, paying people to make sure the test will pass a peer review.

Just to put things into perspective, have you published in a peer reviewed journal? if so, which one? in my experience, they don't care if you pay your subjects or not, as long as you provide evidence that they are viable subjects, usually an audiometry test is enough.

I am betting I can design a test that will show a statistically significant difference between the sound of two amplifiers into a single set of speakers. Using a test that can be peer reviewed and the results published in an academic journal.

Is your test a double blind test? if not, what kind of test is it? in which journal do you think they will aprove such test?

Let me add another thing, we are talking about two amplifiers which are similar in construction right? the entire thread is based on "all power amps good ones sound the same"  for example both solid state, from reputable brands, they don't have to be expensive, but if you want to compare a 1930's single ended home made distortion machine amp with a modern solid state top shelf amp, you could hear a difference,

 

[JohnRoberts]

There will always be a need for subjective tests to compliment data driven tests.
Reason is, any objective quantification of subjective experience modifies subjective preference, especially once the subject knows they can be gamed.

https://www.youtube.com/watch?v=-2SvMeyeOgQ

its not either or, sound good, or measure good, it needs to do both "AND" be perceived as being good, so good cosmetic design, brand management, etc.

In console design I killed braincells wrestling with ergonomic factors like pot gain laws, tapers, EQ voicing, etc. Not objective performance factors, but certainly matter to the meat in the seats.

JR

 

[Gold]

Just to put things into perspective, have you published in a peer reviewed journal? if so, which one? in my experience, they don't care if you pay your subjects or not, as long as you provide evidence that they are viable subjects, usually an audiometry test is enough.

I have no experience with academia. The only part of the test I need to be involved with is picking the equipment and setting it up. All approved by people who are academics and give it the stamp of approval.

Is your test a double blind test? if not, what kind of test is it? in which journal do you think they will aprove such test?

Of course the test will be set up to meet whatever academic criteria is necessary. As for journals take your pick. AES and the Acoustical Society of America come to mind.

I would meet whatever criteria was used in the AES study to determine if the amplifiers were similar enough.

 

[user 37518]

Well go ahead and do it, what do you need me for? You would be doing a service to the audio community if you can prove that in an unbiased test of similar amplifiers you had a statistically significant result in which users could hear a difference.

 

[Gold]

Well go ahead and do it, what do you need me for?

I am not an academic. I’d need someone to administer the test. Do the statistical analysis, and write the paper.

 

[Gold]

I am a lecturer at a university and currently finishing my PhD in EE

It sounds like you have access to the facilities and personnel to make this happen. It would be very exciting to do this test. I would accept help from tenured acoustics professors who have experience setting up these tests.

 

[scott2000]

I got 5 on it

 

[john12ax7]

@user 37518, are you sure you are not letting your own bias influence your objectivity?  You misread bluebird's post thinking it "proved your point" but missed the very important distinction between converters and amps. And the link you provided doesn't actually support things either. It is perhaps surprising that many people preferred the cheaper amp setup. Maybe it shows that expensive gear isn't always preferable.  But the fact that most people had subjective preferences implies that there ARE audible differences, which was the subject of this thread.

 

[Gold]

I would love to see this test conducted. I am not qualified to set up a Double Blind Whoopee Ha Ha. user 37518 is not qualified to set up a Double Blind Whoopee Ha Ha. We would need someone who is competent to set it up. There doesn't seem to be much curiosity in finding out the answer. I guess an engineering student could be forgiven for not having the curiosity of a scientist.

 

[Gold]

But the fact that most people had subjective preferences implies that there ARE audible differences, which was the subject of this thread.

I guess I should have read the paper. I didn't know they gave out PhD's at community college.